On a recent weekday at the Old Globe Theatre, the disembodied top floor of a three-story home dangled high above the stage, waiting to be fitted with its foundation.

The house that hosts the Globe production of “August: Osage County” is so massive that the theater had to tear out some stage structures to create enough vertical space for it. Yet in a way, the effort seems beside the point, because the play itself promises to raise the roof.

Tracy Letts’ epic family saga, winner of the Pulitzer Prize in 2008 and a long-running Broadway hit, comes to the Balboa Park theater packing a well-deserved rep for transgression in the name of entertainment. It’s a three-act, three-hour-plus pulp opus about an Oklahoma household shot through with drug abuse, infidelity, sexual misconduct and all manner of sheer meanness.

The kicker: A lot of people call it a comedy.

“It is filled with laughter,” says Robert Foxworth, the Old Globe associate artist who portrays the work’s battered patriarch, Beverly Weston. “It is one of the funniest American plays ever. But it’s that real, genuine humor that comes out of someplace really deep. Sometimes you’ll find yourself even eating your laugh. Like, ‘Oh my God, did I laugh at that?’

“And I think it’s funny in the way that we laugh when we recognize ourselves and our family. It evokes memory and recall. Not that I know anyone who has a family like this one. But it sparks things.”

In “August,” much of that sparking comes courtesy of the chain-smoking, pill-popping Violet, Beverly’s wife and a witheringly dismissive mom to their three daughters. Also on hand are various husbands and other family members; they’ve all come to the homestead to stand vigil for the missing Beverly, who appears in the play only for a short prologue.

The original production of “August: Osage County” went up in 2007 at Steppenwolf Theatre in Chicago, where Letts (previously known for such works as “Killer Joe,” “Bug” and “Man From Nebraska”) is a longtime ensemble member. Its subsequent Broadway staging won five Tony Awards, including best play, and spawned a U.S. tour.

The Globe’s production is an entirely new one by the rising New York director Sam Gold (“Circle Mirror Transformation”) and features Lois Markle as Violet. Besides Foxworth, she’s joined by Globe associate artist Robin Pearson Rose, as well as Carla Harting (seen recently in “Becky’s New Car” at North Coast Rep), Joseph Adams, Guy Boyd, Todd Cerveris, Kimberly Guerrero, Ronete Levenson, Robert Maffia, Kelly McAndrew, Angela Reed and Haynes Thigpen.

Foxworth, a Broadway veteran who now lives in Encinitas, happens to know the play inside and out. He spent six months in the Broadway production starting in June 2008, in the role of Charlie Aiken, a brother-in-law of Beverly’s.

Now he’s in a part that amounts to perhaps 10 minutes of stage time — and he couldn’t be happier.

On Broadway, Foxworth recalls, “I would be offstage every night listening to (Beverly’s) prologue,” which came shortly before his first scene. “I thought, someday I’d like to do that role.”

The part may be fleeting, but as Foxworth observes, “They talk about (Beverly) constantly. What could be better? And he grows in stature as they talk about him.”

The puzzle over where Beverly has gone is just one of the play’s points of intrigue, says Markle, whose Broadway career stretches back to the early 1960s.

“It’s a play of a lot of mysteries,” Markle says. “I just think the reason it was so welcomed by (audiences) is that it seems to be people you know, and it isn’t. They all have secrets. One of the lines I say in the play is, ‘Secret crushes, secret schemes.’

“The people are ordinary. The play is not.”

To Gold, that sense of the familiar interwoven with the peculiar — and even perverse — gets to the heart of why he wanted to do the piece.

“I really responded, when I read the play, to how deeply true and resonant this family is,” Gold says. “Every detail of every character reminds you of your own family in a very particular way, and in another way, it’s a play about the American family in a broader sense.

“I got excited about putting something onstage that felt very recognizable and very real.”

In order to convey the precise sense of “what a family in crisis feels like,” Gold felt he had to get to know the play’s world a bit better. So he and set designer David Zinn traveled to its real-life setting of Pawhuska, Okla., about 50 miles from Letts’ hometown of Tulsa.

“I’m from New York, so I don’t have a lot of experience with that part of the country, and I wanted to get familiar with the landscape,” says Gold. “Things as specific as how incredibly loud the cicadas are in Oklahoma. (Although) if you put that onstage, people wouldn’t believe it. It would drown everything out.”

The two also went on a house tour there, and settled on “a very specific Craftsman (home)” as the model for the Globe set.

Gold has drawn on one additional primary source — the playwright himself.

Letts “has been very cool about it,” the director says of their conversations. “He’s very interested in seeing (the play) with fresh eyes.” (Gold adds that Letts probably will come to a Globe performance.)

And as for those fresh eyes: Gold says he’s not intimidated in the least at the task of taking this hugely acclaimed play and, like that towering house, building a fresh retelling from the ground up.

“The plays live forever and the productions don’t,” he says. “The text is where it all starts.”